Heat transfer system and electric controls therefor



y 22, 56 R. B. LEACH. 2,746,724

HEAT TRANSFER SYSTEM AND ELECTRIC CONTROLS THEREFOR Filed Dec. 15, 1954 5 Sheets-Sheet 1 T INVEIWUR R,B.Lec2ch y 1956 R. B. LEACH 2,746,724

HEAT TRANSFER SYSTEM AND ELECTRIC CONTROLS THEREFOR Filed Dec. 13, 1954 3 Sheets-Sheet 2 FnoM WATER SUPPLY THERMOS TA L K mo 02 V4 r/ n4 AQUA STAT /4- Q16 INVENTOR R BuLea o h ATTORNEY.

May 22, 1956 R. B. LEACH 2,746,724

HEAT TRANSFER SYSTEM AND ELECTRIC CONTROLS THEREFOR Filed Dec. 13, 1954 3 Sheets-Sheet 3 IN VENTOR R.B.Leac/z ATTORNEYS United States Patent Office 2,746,724 Patented May 22, 1956 HEAT TRANSFER SYSTEM AND ELECTRIC CONTROLS THEREFOR Ray B. Leach, Fremont, Nebr. Application December 13, 1954, Serial No. 474,780

2 Claims. (Cl. 257-3) This invention relates to a heat exchange device, and more specifically to a heat transfer system and electric controls therefor, especially designed for use in mobile homes, such as trailers, and which may be easily adapted for other similar usages.

One of the primary objects of this invention is to provide means for supplying a mobile home with a source of hot water for domestic use, and means for heating the air therein.

Another object of this invention is to provide air cooling and dehumidifying for trailer vehicles.

A still further object of this invention is to provide a device of the type described above which occupies a relatively small space, and which is compactly assembled.

As a further object of this invention, it is contemplated to provide a heating and cooling system of the type to which reference has been made, the system being inexpensive to manufacture and to maintain, non-complex in construction, and durable in use.

Other and further objects and advantages of this invention will become more apparent from a consideration of the following specification when read in the light of the annexed drawings, in which:

Figure 1 is a side elevation of a heating and cooling system constructed in accordance with the teachings of this invention.

Figure 2 is a detail cross-sectional view of a centrifugal blower, taken on the vertical plane of line 22 of Figure 1, looking in the direction of the arrows.

Figure 3 is a schematic view of the water distribution system employed in the instant invention.

Figure 4 is a wiring diagram for the control apparatus used in conjunction with the water distribution system.

Figure 5 is a side elevation of a heating and cooling system constructed in accordance with a modification of this invention, the pipes or conduits utilized therein being schematically represented.

Referring now more specifically to the drawings, reference numeral indicates, in general, a conventional water heater having a water tank (not shown) and a burner 12 disposed at the lower end thereof, the burner being adapted to consume propane, natural gas, or other types of fuels on low consumption and extremely fast recovery bases. One end of a conduit 14 is connected with the upper end of the heater 10, the other end of the conduit 14 is connected with one side of a normally open three-way valve 16. The second side of the threeway valve 16 is connected to one end of a conduit 18 having the other end thereof connected with one end of a copper coil 20 which comprises a radiator or heat transfer device and is designated, in general, by the reference numeral 22. The other end of the coil 2% is connected with one end of a conduit 24 having its other end connected with one side of a normally open three-way valve 26. The second side of the three-way valve 26 is connected to a sewage drain through the pipe 28 when the valve 26 has been moved from its normally open position. The third side of the valve 26 is connected with one end of a conduit 30 having its other end connected with the suction or intake side of a water pump 32. Conduit 34 connects the output side of the pump 32 with the lower end of the water compartment or tank of the heater 10 to complete the water distribution circuit.

The pump 32 is mounted on one side of a substantially rectangular base 36 by means of bolts 38. The base 36 also supports an electric motor 40 having a V-pulley 42 connected with.a second V-pulley 44 fixedly secured to one end of the drive shaft 46 of the pump 32 for rotation therewith. Pulleys 42 and 44 are placed in driving relation through the endless V-belt 47.

The other end of the drive shaft 48 of the motor 40 is connected with the impeller blades 50 (see Figures 1 and 2) of a centrifugal blower 52. The side wall 54 of the blower 52 is connected by means of a substantially cylindrical sleeve 56 with one end of a plenum chamber 58 which surrounds the coil 20 of the heat transfer unit 22. The lower end of the plenum chamber 58 is provided with an aperture 61 to permit the passage of air therethrough. The other side of the plenum chamber 58 is connected with an air intake circuit which is open at its outer end to the ambient atmosphere. The centrifugal blower 52 discharges air drawn therein through a discharge pipe 62 which may be, if desired, also connected with a plenum chamber not shown.

One end of a conduit 64 is connected with a source of water under pressure, while the other end thereof is connected through a T-connector 66 and a pipe 68 with the water tank of the heater 10 in order to insure a constant supply of water thereto.

The T-connector 66 has its other side connected to one edge of a pipe 70 which has its other end connected with a normally closed solenoid operated valve 72, and the latter is connected through the conduit 74 with. the three-way valve 16. The valve 16 normally presents its closed side to the adjacent end of the pipe 74.

Hot water for domestic use may be drawn from the heater 10 through the discharge conduit 73.

In this embodiment of the invention, water under pressure enters the conduit 64 and passes to the lower end of the water tank within the heater 10, and upon being heated is passed therefrom through the pipe 14, the normally open three-way valve 16, the conduit 18, and into the coil 20. The heated water discharges from the coil 20 through the conduit 24 and is passed through the normally open three-way valve 26, the conduit 30, pump 32, conduit 34, and into the lower end of the tank of the heater 10.

During the above described circulation of the water, the motor 40 has been energized by an electrical circuit to be described, and the motor 40 simultaneously drives the pump 32 and the impeller blades 50. During this operation fresh air is drawn into the centrifugal blower 52 through the sleeve 50 and in so doing passes over the heated coil 20 in a heat-transfer relation. Air from the interior of the trailer is also drawn through the plenum chamber for the coil 20 through the opening 61 and is passed there-across for recirculation into the trailer. The heated air is then discharged from the discharge pipe 62 into the interior of the trailer.

The above described circulation of water, the operation of the motor and the pump, and the relationship of the valves presupposes that the described unit is to be employed as a heating device.

' The unit is controlled by an electrical circuit which includes a thermostat and an aquastat. The thermostat is of conventional construction and is provided with two sets of contact points, of these one is designed to close when the surrounding atmosphere has reached a predetermined low temperature, and the other thereof is adapted to open when the ambient atmosphere has reached a predetermined high temperature.

Referring now more specifically to Figure 4 of the drawings, the electric circuit in whichthe thermostat is connected comprises a pair of leads 100, 102 having their respective ends adapted for connection with a source of electrical energy.

The lead 100 connects through wire 104 with one con tact of the thermostat 106. The other contact of the thermostat 106 connects with one side of the winding 108 of a magnetic relay switch 110 through wire 112. The other side of the winding 108 is connected through wire 116 with one side of an aquastat 114 which is disposed within the tank of the heater 10. The other side of the aquastat is connected through wires 118 and 120 with the other line 102. Thus it is seen that the magnetic relay coil 108 and the aquastat 114 are connected in series.

The aquastat is of such construction as to hold its switch in open condition until the water within the heater has reached a predetermined high temperature. Until this condition is obtained the magnetic relay switch 110 is inoperable.

Reference numeral 122 designates, in general, a single pole, double throw, manually operated switch. When the heating system described above is to be rendered operative, the switch arm 124 is moved into engagement with the fixed contact 126.

Now let it be assumed that the thermostat 106 is demanding the operation of the heating system. The closure of its contacts establishes the series circuit referred to above, and assuming that the water within the heater 10 has been heated to or above the predetermined value, and the Winding 108 is energized, Energization of the winding 108 effects movement of the switch arm 128 against the fixed contacts 130 and 132. The energization of the coil 108 also ettects movement of the switch arm 134.

As is seen in Figure 4 of the drawings, a circuit is now established from the line 100 through the switch arm 124, fixed contact 126, wire 136, binding post 138, wire 140, the fixed contact 132, switch arm 128, fixed contact 130, wire 140, binding post 142, wire 144 and Wire 146 to one side of the motor 40. The other side of the motor 40 is connected to the lead 102 thus completing the circuit to the motor. As the motor 40 is energized, the pump 32 is activated and the water in the heating system is circulated through the coil 20 to heat the air in the manner described above. Simultaneously, the centrifugal blower 52 is also set into operation.

When the air within the trailer has reached a predetermined high temperature value, the contacts of the thermostat 106 open thereby deenergizing the winding 108 which releases the switch arms 128 and 134, the latter now move to their positions as shown in Figure 4. The release of the switch arm 128 interrupts the circuit to the motor 40 rendering it inoperative, and as a result thereof, the pump and centrifugal blower are both rendered inactive.

The motor is energized and deenergized alternately, upon the closing and opening of the switch contacts of the thermostat 106 providing, of course, that the contacts of the aquastat114 remain closed.

Assuming that the described system is to be used as an air cooling device, the switch arm 124 of the switch 122 is moved into engagement with the fixed contact 148. The other set of contacts in the thermostat 106 are set to close when the ambient atmosphere has reached a predetermined low temperature value.

The heating system is conditioned by removing the pulley belt 47 rendering the pump inoperative. The pipe 24 is placed into communication with the drain pipe 28 by manually operating the three-way valve 26, and the valve 16 is turned to connect pipe 74 with the pipe 18.

In Figure 4 of the drawing, the position of the switches 128 and 134 appear in their respective positions if the thermostat 106 was demanding operation of the unit. In this case it is seen that the solenoid operated valve 72 is energized through line 100, wire 104, switch arm 124, contact 148, wire 150, wire 152, binding post 154, fixed contact 156, switch arm 128, fixed contact 158, binding post 160, and wire 162 to one side of the solenoid control valve 72. The other side of the solenoid valve 72 connects through wire 164 to the other line 102.

Energization of the valve 72 permits water to pass from the tank 10 through the pipe 68, T-connector 66, pipe 70, the solenoid valve 72, pipe 74, valve 16, and pipe 18 into the coil 20. The water is discharged from the coil 20 through pipe 24, valve 26, and discharge or drain pipe 28.

At the same time, the motor is energized through a circuit which includes the line 100, switch arm 124, fixed contact 148, wire 150, binding post 166, fixed contact 168, switch arm 134, and the fixed contact 170, which conmeets with one side of the motor 40 through wire 146. The other side of the motor being connected with the line 102 is thereby energized.

The energization of the motor 40 effects operation of the centrifugal blower 52 whereby air is drawn into the plenum chamber 22 across the coil 20 in heat transfer relationship. The cooled air is discharged from the blower 52 into the trailer in the manner described above.

It will be recognized that the circulation of the water through the coil 20 is dependent upon the pressure of the water entering the system through the pipe 64.

When the trailer has been cooled to a predetermined low temperature value, the contacts of the thermostat 106 close to energize the coil 108 through a circuit which includes the line 100, wire 104, thermostat 106, wire 112, coil 108, the aquastat 114 (set to closed position), wire 118, and through wire to the other of the lines 102. The energization of the winding 108 causes the switch arms 128 and 134 to break contact with the fixed contacts 156, 158, and 168, breaking the circuits to the motor 40 and the solenoid valve 72 which then closes.

This cycle of operations continues alternately as the temperature within the trailer rises and falls.

In the modification of the invention illustrated in Figure 5 of the drawings, reference numeral 200 designates, in general, a conventional water heater having a water tank 202. The heater 200 includes a burner 204 disposed below the lower end of the tank 202, the burner being adapted to consume propane, natural gas, or other types of fuels on low consumption and extremely fast recovery bases.

Water from a main enters the upper end of the pipe 206 and passes through a T-connector 208 to the tank 202 through the pipe 210. Water heated by the burner 202 is discharged through the pipe 212 and the normally open valve 214 into one end of a pipe 216. Water in the pipe 216 is discharged into one end of a coil 218 enclosed within a suitable plenum housing 220. One end of a pipe 222 is connected with the discharge end of the coil 218, and the other end of the pipe 222 connects with one side of a three-way valve 224. The second side of the valve 224 is connected with one end of a drainage or discharge pipe 226, and the third side of the threeway valve 224 is connected through pipe 228 with the suction side of a pump 230. The discharge side of the pump 230 is connected through pipe 232 with the lower end of the heater tank 202.

One side of the T-connector 208 is connected with one end of a pipe 234, the latter having the other end thereof connected with one side of a solenoid operative valve 236. The other side of the solenoid valve 236 connects through pipe 238 with the third side of the three-way valve 224.

A motor 240 is mounted on a motor block 242 and is secured thereto by bolts 244. The block 242 is supported from hangers 246 which project laterally from the casing of the centrifugal blower 248 and plenum chamber 220. Additional supporting blocks or plates 250 may be inserted between the casing 220 and the lower end of the motor block 242.

Reference numeral 252 designates, in general, a plenum chamber, including a housing 254 and a baffie 256. The lower end of the housing 256 is provided with a plurality of air inlet ports 258 above which is located a manually operated damper 260 as is seen in the drawings, the damper 260 is mounted for rotation on the dia metrically extending shaft 262.

A side of the housing 254 is provided with a vertically extending substantially rectangular slot having a pair of vertically extending guide members 258 disposed along the marginal side edges thereof. A pair of closure members 263, 265 are slidably mounted within the side mem bers 258.

The plenum chamber 252 is connected by means of a collar 255 with the intake side of the centrifugal pump 248.

Compressed air is discharged from the lower end of the pump 248 into the upper end of the plenum chamber 220 for circulation around the coil 218. The air from the plenum chamber 220 is discharged through an elongated substantially rectangular and horizontal slot 264.

The impeller blades of the centrifugal blower pump 243 are driven by one end of the drive shaft 266 of the motor 240. A pulley 268 is mounted on the other end of the drive shaft 266 and is connected by an endless V-belt 270 with a second pulley 272 fixedly secured on the drive shaft 274 of the water pump 230. The pump 230 is supported on the motor block or base 242 by means of an L-shaped bracket 276 and fastening bolts 278.

From the foregoing it is deemed that the water circulatory system is most evident. Water from the main passes through pipe 206, pipe 210 into the heater tank 202. The water heated by the burner 204 is discharged through pipe 212, the normally open three-way valve 214 and into the pipe 216. Under these conditions, the solenoid valve 236 is in its normally closed position.

The hot water passes from pipe 216 into the coil 218,

and discharges from the latter through the pipe 222 and the normally opened three-way valve 224, into the pipe 228. The water then enters the suction side of the pump 230 from the pipe 228 and is discharged from the pressure side of the pump into the pipe 232 for return to the lower end of the tank 202.

Simultaneously with the flow of water through the system, the motor 240 is energized thereby elfecting the operation of the centrifugal pump 248 as well as the water pump 230.

The actuation of the centrifugal pump or blower 248 causes air under pressure to circulate around the coil 21?) in heat transfer relation, and the heated air is then subsequently discharged through the elongated slot 264 into the trailer. The volume of air passed to the centrifugal blower 248 is controlled by the position of the closure members 263 and 265, and the damper 260.

The operation of this heating unit is controlled by the electrical circuit hereinbefore described.

To convert this heating unit into an air cooling system, the manually operated valve 214 is manipulated to connect pipe 238 with pipe 216, and the manually operated valve 224 is also actuated to place the pipe 222 into open communication with discharge or drain pipe 226. The V-belt 270 is disconnected from the pulleys 268 and 272 in order to render the pump 230 inoperative.

Here again, the above described electric circuit controls the operation of the cooling system.

Assuming that the thermostat 106 is demanding that the cooling unit be operated, the solenoid operated valve 23-6 is energized whereby water passes from pipe 206, T-connector 208, .pipe 234, solenoid valve 236, pipe 238 and through the three-way valve 214 into the pipe 216. From the pipe 216, water passes into the coil 218 and 6 is discharged therefrom from the pipe 222, the valve 224, and the drainage pipe 226. When the trailer or room has been cooled to a predetermined low temperature, the electrical circuit is deenergized by energizing the winding 108, elfecting the closure of solenoid valve 236 and the deenergization of the electric motor 240.

Having described and illustrated two embodiments of this invention, it will be understood that the same are offered merely by way of example, and that the invention is to be limited only by the scope of the appended claims.

What is claimed is:

l. A convertible heat transfer system comprising a water tank, means connecting said tank with a source of water under pressure, means for heating water in said tank, a plenum chamber having a pair of opposed air intake and discharge open ends, a metallic coil radiator disposed in said chamber and having a pair of opposed ends, a first conduit connecting said hot water tank with one end of said radiator, a first manually operated twoway valve connected in said first conduit, a pump, a second conduit connecting the other end of said radiator with the suction side of said pump, a second manually operated two-way valve connected in said second conduit, a water discharge conduit connected with said second manually operated valve, said second manually operated valve being normally open with respect to said second conduit and closed with respect to said discharge conduit, a third conduit connecting the pressure side of said pump with said water tank, a fourth conduit connecting said source with said first manually opera-ted valve, said first manually operated valve being normally open with respect to said first conduit and closed with respect to said fourth conduit, a normally closed solenoid valve connected in said fourth conduit, a second plenum chamber, said second plenum chamber having air intake and discharge open ends, a centrifugal blower mounted in said second plenum chamber, a sleeve connecting said air discharge end of said first chamber with the air intake end of said second chamber and with the suction side of said blower, said blower discharging air from its pressure side through said discharge side of said second plenum chamber, an electric motor, means connecting said motor with said pump and said blower in driving relation, an electric circuit for said motor including a source of E. M. F., thermal responsve circuit con trol means operable to energize said circuit in response to a predetermined low temperature whereby hot water is circulated by said pump through said first, second and third conduits, said first and second manually operated valves, said tank and said radiator, to heat air drawn into said first plenum chamber and to discharge said heated air from said second plenum chamber, said manually operated valves being operable to a second position to cut oil water from said tank to said radiator through said first conduit and to connect said first conduit with said fourth conduit, a second electric circuit for said motor, said second circuit including said motor, said solenoid valve, said source of E. M. F. a normally open thermal responsive control switch, said last named switch closing in response to a predetermining high temperature, whereby water flows from said source through said fourth conduit and solenoid valve, said first valve and conduit, said radiator, and second conduit and second manually operated valve and said discharge conduit, and said means connecting said motor with said pump in driving relation being disconnected therefrom.

2. A heat transfer system comprising a water tank, a first conduit connected with a source of water under pressure and said tank, means for heating said water, a plenum chamber, a coil radiator disposed in said plenum chamber, a second conduit connecting one end of said coil with the upper end of said tank, a third conduit connect-ing the other end of said coil with the lower end of said tank, a first normally open manually operated valve in said second conduit, a second normally open manually operated valve and a pump in said third conduit, a discharge conduit connected with said second valve, said second valve being normally closed with respect to said discharge conduit, a fourth conduit connecting said first conduit with said first valve, said first valve being normally closed with respect to said fourth conduit, a normally closed solenoid valve in said fourth couduit, a blower having its suction side connected with the discharge side of said plenum chamber, an electric motor connected in driving relation with said blower and said pump, a pair of thermally controlled electric circuits for said motor, one of said thermally controlled circuits being energized at a predetermined low temperature and the other at a predetermined high temperature, said low temperature control circuit upon energization energizing said motor to drive said pump and blower and to circulate hot water from said tank through said second conduit and its valve, said coil, and said third conduit, .said first manually operated valve being operable to shut off water from said tank to said second conduit and to connect said second conduit with said fourth conduit, said second manually operated valve being operable to shut off water to said pump through said third conduit and to connect said third conduit with said discharge conduit, said high temperature circuit including said motor and said solenoid valve and upon energization of said motor and opening of said valve efiecting the flow of water through said first conduit, said fourth conduit, said first manually operated valve, said second conduit, said coil, said third conduit and second manually operated valve, and through said discharge conduit, and said means connecting said motor with said pump in driving relation being disconnected therefrom.

References Cited in the file of this patent UNITED STATES PATENTS 

